The part of the claim for restitution of unjust enrichment is reversed, and that part of the case is remanded to the Seoul High Court.

1. As a matter of course, an interpretation of a juristic act shall be based on logical and empirical rules, comprehensively taking into account the content of the juristic act, the motive and background leading up to such juristic act, the purpose to be achieved by the juristic act, the parties’ genuine intent, etc., and shall reasonably interpret it in accordance

(See Supreme Court Decision 2013Da69804 Decided October 29, 2015 (see, e.g., Supreme Court Decision 2013Da69804, Oct. 29, 2015). Meanwhile, in a case where a person benefiting profit lacks a legal cause, the unjust enrichment system imposes the duty of return on the person benefiting profit based on the ideology of equity and justice. As such, the system is designed to resolve such inconsistency by ordering the person benefiting profit to return the value in a case where there is a change in the value of property between a specific party and it seems reasonable in a general form, but the change in property value

Therefore, the issue of whether “legal cause” among the elements for establishing unjust enrichment belongs to the area of normative judgment based on the principle of fairness, and thus, the determination should be reasonably made in consideration of the nature of the act of payment or the responsibility and duty of the person who incurred the payment, etc.

(2) On January 14, 2016, the lower court, citing the reasoning of the first instance judgment, acknowledged the fact that the Plaintiff consented to the Defendant’s use of the money borrowed under the name of the Plaintiff in full view of the circumstances indicated in its holding, and, in so doing, deemed that the Defendant incurred damage to the Plaintiff due to the Defendant’s use of the loan.

It is recognized that the defendant obtained a benefit without any legal cause.